Along with development and increasingly wide application of integrated circuit technology, the design of integrate circuits has to take into account requirements for high reliability, excellent performance and low costs. There is a growing demand for functions and precision in respect of IC CAD software statistical variation tolerance analysis, optimized design, yield rate, cost analysis and prediction of reliability. However, in IC CAD software, device model of MOSFET is a critical link that links IC design and IC product function and performance. As sizes of integrated devices become smaller and smaller, the integration scale becomes increasingly large, and processing of integrated circuits becomes more and more complicated, all of these require greater precision for device models. Today, how to provide a MOSFET model with precision has without doubt become a problem for IC CAD designers to solve urgently; it is also an important and hot research topic across the world. Currently, the mainstream MOSFET device modeling in the industry is BSIM modeling, while correspondingly SOI MOSFET device modeling is BSIMSOI modeling.
The devices corresponding to BSIMSOI is devices having source-drain injection reaching the bottom. However, in the practice of circuit designing, MOSFET usually makes use of device structures having source-drain injection not reaching the bottom in order to facilitate the implementing of body leads along the direction of channel length. This would increase the source body junction bottom capacitance and the drain body junction bottom capacitance, but the traditional BSIM SOI modeling is incapable of accommodating effects of this.